薇甘菊化感作用的初步研究

对薇甘菊(Mikaniamicrantha)提取物乙醇部分的化感作用进行了初步研究。结果表明,薇甘菊提取物乙醇部分对水稻、萝卜、黄瓜、菜心具有不同程度的化感作用,总体上呈现出低促高抑的现象,且随着溶液浓度增大而抑制作用增强。其中干物质为0.1g/ml的乙醇部分溶液对菜心的种子萌发,幼苗生长,根长生长抑制作用最为明显;干物质为0.01g/ml溶液对水稻的根长生长有明显的促进作用;干物质为0.002g/ml溶液对水稻,菜心的种子萌发,幼苗生长,根长生长也有一定的促进作用。     

薇甘菊对桔小实蝇的驱避试验初报

为了探索一种低毒、低残留的环保型驱避剂，分别在广州市番禺区杨桃园和广东省昆虫研究所大院内，以薇甘菊Mikania micrantha H．B．K对桔小实蝇Bactrocera dorsalis（Hendel）成虫进行驱避试验。结果表明，薇甘菊对桔小实蝇具有明显的驱避效果，在薇甘菊环境内诱杀桔小实蝇虫数明显低于正常环境诱杀虫数，全年1，12月薇甘菊环境内对桔小实蝇的驱避率为13．33-92．78％，全年平均驱避率为50．65％；杨桃园内，以薇甘菊甲醇提取物喷施的杨桃，可以把本地种杨桃的桔小实蝇为害率控制在50％以下，而对照的为害率超过80％。     

外来植物薇甘菊的开发利用前景

薇甘菊是一种危害极大的外来入侵植物,近年来薇甘菊防控技术与途径的研究成为薇甘菊研究的热点,但薇甘菊作为一种生物资源也一直受到关注.从薇甘菊在害虫防治、病原微生物防治、生态环境影响以及其他应用等方面进行了详细介绍,并对薇甘菊的开发利用前景进行探讨与展望,以开拓薇甘菊防治的新思路.     

薇甘菊柄锈菌生物学及其寄主专一性

在检疫温室条件下对外来入侵植物薇甘菊的寄生菌——薇甘菊柄锈菌的生物学及其寄主专化性进行了研究。结果表明，薇甘菊柄锈菌可以侵染植物叶片和叶柄等营养器官。受侵染部位起始出现褪绿斑，12～15d，自叶背产生黄色冬孢子堆，并逐步坏死和脱落，最终致寄主死亡。冬孢子黄至暗褐色，包埋在寄主组织中，无明显休眠期。高湿条件下，冬孢子易萌发产生担孢子进行再侵染。采用悬挂法对29个科、62个属的72种植物进行了寄主专化性测定，结果表明，薇甘菊柄锈菌在菊科植物天门冬、紫茎泽兰、向日葵、地胆草上形成褪绿斑，但未发现菌丝和吸器。薇甘菊柄锈菌可成功侵染薇甘菊和同属植物假泽兰。     

薇甘菊中多元素分析及富集研究

本文采用ICP-MS法对薇甘菊不同部位的Pb、Cd、Cr、As、Fe、Mn、Cu和Zn等8种微量元素进行检测,结果显示Fe、Mn、Cu、Zn含量较高,Pb、Cd、Cr和As含量相对较低;不同地区薇甘菊中Pb含量相差较大;不同部位元素含量根中Pb最高,Cu、Zn含量从根、茎、叶依次升高。根据检测结果,从微量元素分布及其富集形态层面对薇甘菊的元素成分进行了剖析,探讨了薇甘菊的综合防治和生物利用前景。     

薇甘菊的天敌调查初报

经调查和鉴定，我国假泽兰属有两种：原产种为假泽兰Mikania cordata,分布海南省和广东省，不造成为害；入侵种为薇甘菊Mikania micrantha，分布广东、香港和台湾等地，造成严重为害。在假泽兰上采到假泽兰瘤瘿螨Aceria mikaniae(Nalepa)，是我国新记录，对假泽兰的生长有较大的抑制作用。薇甘菊有明显的驱避作用，绣线菊蚜Aphis citricolor可致薇甘菊叶片萎缩；在深圳、珠海等地发现薇甘菊上病害普遍，是假尾孢菌属一种真菌Pseudocercospora sp．所致。在有些地方发现菟丝子Cuscuta Japonica Choisy寄生薇甘菊，能否用来抑制薇甘菊的生长，值得探讨。     

薇甘菊柄锈菌在中国南方自然环境下的致病力

将薇甘菊柄锈菌接种于自然环境中,观察薇甘菊发病特征和侵染状况,研究薇甘菊柄锈菌在中国南方自然环境下的适应性和致病力。结果表明:薇甘菊柄锈菌在自然环境下有较好的适应性,接种后的薇甘菊叶片可以出现大量褪绿斑,随后产生黄褐色冬孢子堆,然后逐渐坏死和脱落;并且可以成功侵染野生薇甘菊,完成侵染循环。     

薇甘菊吸附亚甲基蓝的研究

研究薇甘菊活体在不同pH值、初始浓度、吸附时间条件下对水体中亚甲基蓝的吸附能力,并对薇甘菊的再生及重复吸附能力进行测试。结果表明:常温下,在亚甲基蓝溶液浓度为5~20 mg/L、pH值为8的亚甲基蓝溶液中,薇甘菊活体培养3 d后对亚甲基蓝的去除率可达99%。同一株薇甘菊可以在浓度为10 mg/L、pH值为8的亚甲基蓝溶液中循环培养4次吸附效果最佳,去除率均可达到90%以上,吸附效果良好。     

30种除草剂对豚草和薇甘菊的防效初步评价

为了筛选出防除豚草和薇甘菊的新型高效除草剂品种,采用茎叶喷雾法,测定30种除草剂对盆栽豚草和薇甘菊的防除效果。辛酰溴苯腈375 g /hm2、麦草畏216 g /hm2、百草枯600 g /hm2、草铵膦540 g /hm2、草甘膦异丙胺盐922.5 g /hm2、乙羧氟草醚90 g /hm2、三氟羧草醚540 g /hm2、氟磺胺草醚427 g /hm2、莠去津1 140 g /hm2、莠灭净3 000 g /hm2和灭草松1 440 g /hm2对豚草防除效果好,药后30 d鲜重防效达100%;对薇甘菊防效较好的有辛酰溴苯腈375 g /hm2、麦草畏216 g /hm2、2,4-滴钠盐125 g /hm2、氯氟吡氧乙酸180 g /hm2、氯氟吡氧乙酸异辛酯150 g/hm2、草铵膦540 g /hm 2、草甘膦异丙胺盐922.5 g /hm2、灭草松1 440 g /hm2和百草枯600 g/hm2,药后30天鲜重防效达98%以上。本试验结果将为豚草和薇甘菊的化学防控提供有益参考。     

外来入侵性杂草薇甘菊的研究进展

薇甘菊是20世纪80年代末传入我国的一种危害经济作物和森林植被的恶性杂草,原产于热带美洲,现已入侵到南亚、太平洋地区及我国华南地区。本文对薇甘菊的形态分类、生物学和生态学特性、危害性、防治及其综合开发与利用等方面的研究进行综述,并提出自己的研究建议。     

Potential allelopathic effects of Mikania micrantha on the seed germination and seedling growth of Coix lacryma‐jobi

The allelopathic potential of Mikania micrantha H.B.K. to affect the seed germination and seedling growth of Coix lacryma‐jobi L. was investigated. Water‐soluble allelopathic substances were found in the water extracts of M. micrantha. The effect of the water extracts on the seed germination and seedling growth of C. lacryma‐jobi was concentration‐dependent. The water extracts from the different plant parts (leaf, stem, and root) of M. micrantha differed in their effect on the germination and seedling growth of C. lacryma‐jobi, with the effect of the leaf extract being the least inhibitory. The malondialdehyde (MDA) content in the C. lacryma‐jobi seedlings increased by 64%, 45%, and 52% of the control with increasing concentrations of the extracts of the root, stem, and leaf (80, 400, and 400 g L^?1, respectively). The extract from the M. micrantha roots significantly increased the catalase (CAT) activity of the C. lacryma‐jobi seedlings (48% and 54% of the control at the concentrations of 20 g L^?1 and 80 g L^?1, respectively). The extracts from the leaves and stems at low concentrations increased the CAT activity, but at high concentrations, the extracts decreased the CAT activity. The extracts from the roots, stems, and leaves at concentrations of 80, 400, and 400 g L^?1 also significantly decreased the peroxidase (POD) activity of the C. lacryma‐jobi seedlings to 27%, 52%, and 34% of the control, respectively. These results indicate that the water extracts of M. micrantha could inhibit the seed germination and seedling growth of C. lacryma‐jobi through the regulation of anti‐oxidase activity, such as POD and CAT in the cells. The growth inhibition of the C. lacryma‐jobi seedlings is probably related to injury after oxidization of the cell membranes with the increase of MDA content.     

5种化学除草剂对薇甘菊防治效果及对其他植物的影响

为了筛选高效防除薇甘菊的除草剂,本文利用4种含灭草松或吡啶类的新型除草剂25％苄嘧磺隆·灭草松AS、25％滴酸·灭草松AS、25％滴酸·氨氯吡AS、25％氟胺·灭草松AS,以常用除草剂24％滴酸·二氯吡AS作对照,在深圳进行防除薇甘菊的试验研究.除草剂对薇甘菊防效结果表明:400 mL/hm2 25％滴酸·氨氯吡AS和...     

Self-incompatibility in Mikania micrantha in South China

Mikania micrantha is a successful invasive weed in many parts of the world, but we do not know how its mating system may have contributed to this. Therefore, its mating system was studied in an open M. micrantha population during the flowering seasons of 2004 and 2005. Pollen/ovule ratio was determined and pollination treatments were applied on entire inflorescences to estimate the seed/ovule ratio. The pollen/ovule ratio of M. micrantha was 4008, and seed/ovule ratio was 0.56 for open pollination and 0.0034 and 0.0038 for wind pollination and selfing respectively. These data indicate that the weed is self‐incompatible and needs insect pollination.     

三叶鬼针草化感作用的初步研究

运用生物测定法,对三叶鬼针草的化感作用进行研究。比较了用不同部位及其不同浓度水浸提液对不同作物化感作用的差异,并初步探讨了三叶鬼针草对小麦和莴苣幼苗生长的化感机制。结果表明,三叶鬼针草不同部位水浸提液对2种受体植物影响均表现出抑制效应,其强弱为叶>茎>根。其水浸提液对2种受体植物的种子萌发、幼苗生长和光合色素均有显著的抑制作用。Peason相关性分析表明,叶绿素A和叶绿素b含量与水浸提液浓度存在显著的负相关性,类胡萝卜素无明显变化。丙二醛随浓度增加而有上升趋势,但差异不显著,说明三叶鬼针草对受体植物膜的透性影响不大。     

Influence of obligate parasite Cuscuta campestris on the community of its host Mikania micrantha

As a means of biologically controlling Mikania micrantha in South China, the influence of the native obligate parasite Cuscuta campestris on its natural community was studied in the field. Mikania micrantha is a non‐indigenous vine that smothers other vegetation and has become a major invader of agricultural land and native areas in Southern China. These preliminary results showed pronounced effects on M. micrantha by C. campestris. Cuscuta campestris significantly reduced biomass of M. micrantha, increased species diversity and helped re‐establishment of native species. Biomass of M. micrantha decreased from 328 g m^?2 to 82 g m^?2, biomass of companion species increased from 41 g m^?2 to 145 g m^?2, the total number of species increased from 7 to 19 and the species diversity index from 1.8 to 5.6, when C. campestris was present. These results indicated that the use of C. campestris could be a potentially effective way of controlling M. micrantha and could help us achieve the novel objective of biological control of weeds using weeds.     

Seed biology of Mikania micrantha in Viti Levu,Fiji

Mikania micrantha (mile‐a‐minute) reproduces both by seed and vegetatively. A study to determine the possible pollinators, seed production rates, temperature and salinity limitations to germination and its seedbank size and persistence was conducted in Viti Levu, Fiji. Representatives of the Diptera had the greatest percentage of all floral visits (38%), followed by Hymenoptera (34%) and Lepidoptera (27%), while the honeybee was the most recurring visitor (18% of all visits). Flower heads (capitula) within the inflorescence commonly formed four viable seeds, resulting in 60 820 filled seed being produced per m². However, the seedbanks formed were not massive (600 seed m^?2) and they were moderately persistent (T₅₀: 1–3 years). Seed germination from both high and moderate rainfall regions occurred rapidly, under a wide range of temperature regimes, with no primary dormancy being observed. This study indicates that the seed reproductive success of M. micrantha in the two rainfall regions of Fiji is due to a number of factors, including the production of large numbers of flowers, successful pollination by local insects and the subsequent production of a large number of viable seeds. These seeds have high viability, no dormancy and are capable of forming small‐to‐medium seedbanks that are moderately long‐lived. In addition, seeds can germinate under a wide range of temperature and salinity conditions. This knowledge on seed production, biology, longevity and salt tolerance is vital in the development of management plans of M. micrantha in Fiji.     

Potential biological control agents for Mikania micrantha hbk from the Neotropical region

Abstract

Mikania micrantha HBK, a sprawling composite vine native to the Neotropics, is a serious weed of plantation crops in Southeast Asia. A survey and assessment of its natural enemies in the Neotropics reveals nine major natural enemies and over 20 minor ones. The biology of the nine major natural enemies: Acalitus sp. (Acarina, Eriophyiidae), Liothrips mikaniae (Priesner) (Thysanoptera, Phloeothripidae), Teleonemia sp. (Heteroptera, Tingidae), Desmogramma conjuncta Bechyné, Physimerus pygmaeus Jacoby, Omoplata spp. (Coleoptera, Chrysomelidae), Apion luteirostre Gerst. (Col., Apionidae), Pseudoderelomus baridiiformis Champ. (Col., Curculionidae), together with brief accounts of the minor ones, forms the bulk of this paper. The prospects for biological control of M. micrantha are considered reasonable, and an outline for a continuation of work on the project is given, beginning with the introduction of L. mikaniae to Southeast Asia.